StockDriftsStockDriftsThe Kosei Securities Co., Ltd. (8617) has 25 disclosed large-shareholding filings and 23 disclosed disposals on record, filed by 7 distinct investors. Together those filings cover ¥2.3B ($15.0M) in reported transaction value. The earliest filing StockDrifts holds for The Kosei Securities Co., Ltd. is dated 2022-02-21; the most recent is 2026-01-05. Across these filings the average return since disclosure is +23.00%, measured from each filing date to the latest available close.
| Date | Type | Source | Insider | Purpose | Shares | Price at filing | Return | Value |
|---|---|---|---|---|---|---|---|---|
| 2026-01-05 | SELL | unknown | 株式会社巽也蔵 | strategic | 1.9M | ¥466 | -33.3% | ¥18M ($114K) |
| 2026-01-05 | SELL | unknown | 株式会社巽事務所 | strategic | 1.1M | ¥466 | -33.3% | ¥61M ($391K) |
| 2026-01-05 | BUY | unknown | 株式会社哲学の道文庫 | strategic | 912.1K | ¥466 | - | - |
| 2025-11-18 | BUY | Market Buy | 巽 大介 Daisuke Tatsumi | strategic | 540.4K | ¥455 | +36.5% | ¥7M ($45K) |
| 2025-11-18 | BUY | Market Buy | 巽 春菜 Haruna Tatsumi | strategic | 299.0K | ¥455 | +36.5% | ¥96M ($618K) |
| 2025-11-11 | BUY | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.9M | ¥461 | +34.7% | ¥437K ($3K) |
| 2025-11-11 | SELL | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.2M | ¥461 | -34.7% | ¥143M ($920K) |
| 2025-11-11 | BUY | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥461 | - | - |
| 2025-11-10 | BUY | Market Buy | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.6M | ¥470 | +32.1% | ¥80M ($515K) |
| 2025-11-10 | BUY | Market Buy | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.9M | ¥470 | +32.1% | ¥31M ($198K) |
| 2025-11-10 | BUY | Market Buy | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥470 | - | - |
| 2025-08-19 | BUY | Market Buy | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.9M | ¥495 | +25.4% | ¥49M ($315K) |
| 2025-08-19 | BUY | Market Buy | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.4M | ¥495 | - | - |
| 2025-08-19 | BUY | Market Buy | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥495 | - | - |
| 2025-06-05 | BUY | Market Buy | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.8M | ¥411 | +51.1% | ¥41M ($262K) |
| 2025-06-05 | BUY | Market Buy | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.4M | ¥411 | - | - |
| 2025-06-05 | BUY | Market Buy | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥411 | - | - |
| 2025-04-24 | SELL | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.7M | ¥390 | -59.2% | ¥58M ($377K) |
| 2025-04-24 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.4M | ¥390 | +59.2% | ¥58M ($377K) |
| 2025-04-24 | BUY | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥390 | - | - |
| 2024-10-30 | BUY | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥398 | - | - |
| 2024-10-30 | BUY | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.8M | ¥398 | - | - |
| 2024-10-30 | SELL | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.2M | ¥398 | -56.0% | ¥88M ($568K) |
| 2024-10-29 | SELL | Market Buy | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.5M | ¥407 | -52.6% | ¥37M ($237K) |
| 2024-10-29 | BUY | Market Buy | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.8M | ¥407 | +52.6% | ¥87M ($563K) |
| 2024-10-29 | BUY | Market Buy | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥407 | - | - |
| 2024-05-08 | SELL | unknown | 日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd. | other | 21.9K | ¥637 | +2.5% | ¥11M ($74K) |
| 2024-05-08 | BUY | unknown | 三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd. | other | 408.8K | ¥637 | -2.5% | ¥257M ($1.7M) |
| 2024-01-25 | SELL | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.6M | ¥590 | -5.3% | ¥108M ($697K) |
| 2024-01-25 | SELL | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.6M | ¥590 | -5.3% | ¥108M ($697K) |
| 2024-01-25 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.5M | ¥590 | +5.3% | ¥46M ($296K) |
| 2024-01-25 | SELL | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥590 | -5.3% | ¥6M ($40K) |
| 2024-01-25 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.5M | ¥590 | +5.3% | ¥46M ($296K) |
| 2024-01-25 | SELL | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 912.1K | ¥590 | -5.3% | ¥6M ($40K) |
| 2023-09-05 | SELL | Market Buy | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.5M | ¥626 | +0.8% | ¥94M ($605K) |
| 2023-09-05 | BUY | Market Buy | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 922.1K | ¥626 | - | - |
| 2023-09-05 | BUY | Market Buy | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.8M | ¥626 | -0.8% | ¥94M ($609K) |
| 2023-09-04 | BUY | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.6M | ¥632 | - | - |
| 2023-09-04 | SELL | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.6M | ¥632 | +1.7% | ¥127M ($816K) |
| 2023-09-04 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.6M | ¥632 | -1.7% | ¥95M ($611K) |
| 2023-09-04 | BUY | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 922.1K | ¥632 | - | - |
| 2023-09-04 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.6M | ¥632 | -1.7% | ¥95M ($611K) |
| 2023-09-04 | BUY | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 922.1K | ¥632 | - | - |
| 2023-08-28 | SELL | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.6M | ¥586 | -6.0% | ¥117M ($757K) |
| 2023-08-28 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.5M | ¥586 | +6.0% | ¥152M ($983K) |
| 2023-08-28 | BUY | unknown | 株式会社哲学の道文庫 Tetsugaku no Michi Bunko Co., Ltd. | strategic | 922.1K | ¥586 | - | - |
| 2023-02-24 | BUY | unknown | 株式会社巽事務所 Tatsumi Office Co., Ltd. | strategic | 1.5M | ¥389 | +59.6% | ¥101M ($652K) |
| 2023-02-24 | BUY | unknown | 株式会社巽也蔵 tatumiyagura CO.,LTD | strategic | 1.8M | ¥389 | - | - |
| 2023-02-24 | BUY | unknown | 巽 大介 Daisuke Tatsumi | strategic | 525.4K | ¥389 | +59.6% | ¥202M ($1.3M) |
| 2023-02-24 | SELL | unknown | 巽 春菜 Haruna Tatsumi | strategic | 88.0K | ¥389 | -59.6% | ¥31M ($200K) |
Showing the 50 most recent of 74 filings.
Every trade listed above comes from an official regulatory disclosure. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.